Display panel or portion thereof with a transitional graphical user interface



FIG. 1 is a front view of a display panel or portion thereof with atransitional graphical user interface showing a first image in thesequence showing my new design;

FIG. 2 is a front view of a second image thereof;

FIG. 3 is a front view of a third image thereof;

FIG. 4 is a front view of a fourth image thereof;

FIG. 5 is a front view of a fifth image thereof;

FIG. 6 is a front view of a sixth image thereof; and,

FIG. 7 is a front view of a seventh image thereof.

The broken lines around the Figures show a display panel or portionthereof, and form no part of the claimed design.

The appearance of the transitional image sequentially transitionsbetween the images shown in FIGS. 1-7. The process or period in whichone image transitions to another image forms no part of the claimeddesign.

CLAIM The ornamental design for a display panel or portion thereof witha transitional graphical user interface, as shown and described.